This invention relates generally to fluorescent lamps and more particularly to fluorescent lamps that have desirable properties related to the lamps' consumption of mercury and warm-up, or lumen run-up, times.
Fluorescent lamps have found widespread acceptability in the market place for a number of applications and are available in a variety of shapes and forms. For example, the lamps may be linear, curvilinear, U-bent and compact in shape as will be familiar to those having ordinary skill in the art. Typically, fluorescent lamps include a light-transmissive glass envelope with means such as electrodes, for example, for providing an electric discharge to the interior of the glass envelope. A phosphor layer typically applied to the inner surface of the glass envelope comprises the source of the light that the lamp emits. A rare gas and mercury are sealed within the glass envelope, and the mercury functions to excite the phosphors' electrons resulting in the production of light by the lamp in a manner familiar to those having ordinary skill in the art.
Disposing of fluorescent lamps after they have served their useful lives can be problematic because the mercury in the lamps can present environmental concerns. As a result, for reasons related to the environmentally safe disposal of the lamps, it can be useful to minimize the mercury dosages inserted into the glass envelopes during the manufacture of the lamps. A confounding factor in this regard is that the mercury in the fluorescent lamps can be consumed in one manner or another within the glass envelope during operation of the lamps, such as by being taken up by the components and surfaces within the glass envelope for example. Consequently, it is necessary to add sufficient mercury to the lamps during their manufacture to account for the consumption of the mercury so that an adequate amount of mercury will otherwise be available to support the proper operation of the lamps during their lifetimes. Thus, it would be desirable to have available fluorescent lamps wherein the consumption of mercury is such that the lamps can be dosed with a quantity of mercury that allows for the acceptable performance of the lamps throughout their lives while at the same time alleviates the environmental concerns that the mercury presents when the lamps are disposed.